1. Field of the Invention
This invention relates to a method and an article of manufacture to enhance document security, and in particular to provide an authenticating link between a document and the person offering the document for use.
2. Description Relative to the Prior Art
The proliferation of credit card and other paper based transactions in retail and commercial dealings has resulted in a rise in accompanying fraudulent losses to consumers, banks, and businesses. Many remedial countermeasures to the counterfeiting and fraudulent use of credit cards and other personally identifiable documents have been disclosed. For convenience of discussion, the problem is herein considered in terms of credit card usage, although the considerations are readily broadened to determination of user authorization for other personally identifiable documents. In terms of credit card use, those countermeasures wherein there is no confirmation at the point of sale that the offeror of the credit card is, in fact, the authorized user of the card have been readily compromised by the counterfeiting of the card itself. Such counterfeiting is within the capabilities of at least some modern, sophisticated criminals.
A more secure method ties the user at the point of sale to the card by incorporating into the card some unique non-forgeable feature of the person to whom the card is issued. A person's fingerprint is one such unique feature, and systems in which the incorporation of an optical image of the fingerprint replicated on the card has been disclosed include Classen et al (U.S. Pat. No. 3,383,657), Elmes (U.S. Pat. No. 4,455,083), and Ruell (U.S. Pat. No. 4,532,508). In presenting the card for use, the user also places his finger in an authenticating apparatus containing a scanner which scans his actual fingerprint while a card reader in the apparatus scans the optical image of the fingerprint replicated on the card. The authenticating apparatus compares the data derived from the two scans, and if they match the card offeror may be approved as the authorized user of the card.
As the image of the fingerprint is to be optically scanned by the reader, the print on the card must be clearly visible. With continued use, the print may become obscured by dirt or scratches, causing errors in the scanned data which defeat system reliability. Also, the visibility of the print mitigates against the security of the card in that a potential counterfeiter gains the advantage of readily determining the form and substance of the key element in the system. This information may be of substantial help to him in an attempt to compromise the security system by counterfeiting the card and fingerprint.